Improvement in screw-propellers



L. G. & G. F. CARY.

Screw-Propellers.

N0.166,498. Patented'Aug .10,I875.

WITNESSES 4 INVENTDB Hb I BY. m 3.91101 I V ATTOBN UNITED STATES PATENT OFFICE.

LEWIS O. GARY AND GEORGE F. GARY, OF PORTLAND, MAINE.

IMPRO VEMENT IN SCREW-PROPELLERS.

Specification forming part of Letters Patent No. 166,498, dated August 10, 1875; application filed May 1, 1875.

To all whom it may concern:

Be it known that we, LEWIS CLARK GARY and GEORGE FRANCIS GARY, of Portland, in the county of Cumberland and State of Maine, have invented a new and Improved Screw- Propeller, of which the following is a specification:

The invention will first be described in connection with drawing, and then pointed out in the claims.

Figure 1 is a side elevation of our improved propeller with a part in section. Fig. 2 is a section taken on the line 00 :17. Fig. 3 is a section on line y y, and Fig. 4 is a section on line z 2.

Similar letters of reference indicate corresponding parts. I

A represents the blades, which are in length equal to about half the radius of the wheel, and of uniform breadth, being connected at the inner end to the short arms B, and at the outer end to the guard-ring 0. They are molded in concave form at the inner end on the side acting against the water, and for made water-tight to make the ring buoyantthe short blades and small attaching arms improves the efficiency of the wheel by the greater clearance afforded for the water, which does not give beneficial results on the center portion of the blades when they extend thereto. This protecting and buoying ring is applicable to wheels of any form, and may be applied readily to those in use.

Havingthus described our invention, we claim as new and desire to secure by Letters Patent-- 1. The combination of a hollow water-tight protecting-rim with the blades of a propeller,

substantially as specified.

2. The protecting-rim, constructed of the flat band D, oval or half-round band E, and the stiffening-rim F, substantially as specified.

LEWIS O. GARY. GEORGE F. GARY.

Witnesses:

'JoNAH H. DRUMMOND, CHARLES L. DRUMMOND. 

